Valve and method for controlling flow in tubular members

ABSTRACT

Further disclosed herein is a method for controlling fluid flow. The method includes, selectively deforming at least one selectively deformable member disposed between two tubular members that are radially aligned with one another, at least one of the at least one deformable member being positioned between a fluid inlet and a fluid outlet. The method further includes regulating flow of fluid by deforming the at least one deformable member positioned between the fluid inlet and the fluid outlet sufficiently to achieve a desired flow rate.

BACKGROUND OF THE INVENTION

Control of fluid flow through various parts of a wellbore is importantfor optimizing production. Valves to control fluid flow have beendeveloped and are widely used. In some situations it is sufficient touse a valve with only two settings, fully open and fully closed. Inother situations it is desirable to be able to choke the flow withoutshutting it off completely. As wells become more sophisticated there isa desire for increasing accuracy in flow control.

The increasing sophistication of wells also includes an increase inoperating costs and consequently an increase in cost for time in which awell is not producing. Failure of flow control valves is, therefore, acostly and undesirable condition. Accordingly, the art is in need ofhighly durable flow control valves that have highly accurate flowcontrol.

BRIEF DESCRIPTION OF THE INVENTION

Disclosed herein is a valve. The valve includes, a first tubular memberhaving at least one port extending through a wall thereof and a secondtubular member at least partially radially aligned with the firsttubular member. The first tubular member and the second tubular memberare sealably connected at an interface therebetween, one of the firsttubular member and the second tubular member supporting at least onesealable member capable of sealingly engaging the other of the firsttubular member and the second tubular member, and having a portionmovable relative to the interface, the movable portion being located ona first side of the at least one sealable member that is opposite asecond side of the at least one sealable member on which the interfaceis located.

Further disclosed herein is a valve. The valve includes a first tubularmember having at least one port extending through a wall thereof, asecond tubular member radially aligned with and moveable relative to thefirst tubular member, one of the first tubular member and the secondtubular member supporting at least two metal members capable ofsealingly engaging the other of the first tubular member and the secondtubular member.

Further disclosed herein is a method for controlling fluid flow. Themethod includes, selectively deforming at least one selectivelydeformable member disposed between two tubular members that are radiallyaligned with one another, at least one of the at least one deformablemember being positioned between a fluid inlet and a fluid outlet. Themethod further includes regulating flow of fluid by deforming the atleast one deformable member positioned between the fluid inlet and thefluid outlet sufficiently to achieve a desired flow rate.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numberedalike:

FIG. 1 depicts a tubular valve with a single sealable member in anunactuated position;

FIG. 2 depicts the tubular valve with a single sealable member of FIG. 1with the valve in an actuated position;

FIG. 3 depicts an alternate tubular valve with a single sealable memberin an unactuated position;

FIG. 4 depicts the tubular valve with a single sealable member of FIG. 3with the valve in an actuated position;

FIG. 5 depicts a tubular valve with dual sealable members with onesealable member in an unactuated position and the other sealable memberin an actuated position; and

FIG. 6 depicts a tubular valve with dual sealable members with bothsealable members sealingly engaged.

DETAILED DESCRIPTION OF THE INVENTION

A detailed description of several embodiments of the disclosed apparatusand method are presented herein by way of exemplification and notlimitation with reference to the Figures.

Referring to FIGS. 1 and 2, an embodiment of the tubular valve 10 isillustrated. The tubular valve 10 includes a first tubular member 14, asecond tubular member 18 and a sealable member 22. The sealable member22 is supported by the second tubular member 18 and is sealablyengagable with the first tubular member 14 in response to a selectablerepositioning of the sealable member 22. Referring specifically to FIG.1, the sealable member 22 is not sealably engaged with the first tubularmember 14 when the sealable member 22 is in an unactuated position 26 asshown. Referring specifically to FIG. 2, the sealable member 22 issealably engaged with the first tubular member 14 when the sealablemember 22 is in an actuated position 30 as shown. An annular space 34exists between an inner surface 38, of the first tubular member 14, andan outer surface 42, of the second tubular member 18, and provides afluid flow path therethrough. In the actuated position 30 the sealablemember 22 sealably engages the inner surface 38 thereby fully occludingthe annular space 34 and closing the tubular valve 10 to fluidic flowtherethrough. By contrast, in the unactuated position 26, the sealablemember 22 does not occlude the annular space 34 at all and therebydefines a fully open condition of the tubular valve 10. The sealablemember 22 can also occlude a fractional portion of the annular space 34between fully closed and fully open. When doing so the amount ofocclusion varies in proportion to the amount of extension of thesealable member 22 between the unactuated 26 and the actuated 30positions. It should be noted that while the foregoing embodiment hasthe sealable member 22 supported by the second tubular member 18,alternate embodiments could just as well have a sealable membersupported by, or integrated into, the first tubular member 14. Such analternate embodiment could have a sealable member extend radiallyinwardly to sealably engage with the outer radial surface 42 of thesecond tubular member 18, for example.

Repositioning of the sealable member 22, in the second tubular member18, is in one embodiment due to construction thereof. The sealablemember 22 is formed from a section of the second tubular member 18 thathas three lines of weakness 46, 50, and 54, specifically located bothaxially of the tubular member 18 and with respect to an inside surface58 and the outer surface 42 of the second tubular member 18. In oneembodiment, a first line of weakness 46 and a second line of weakness 50are defined in this embodiment by diametrical grooves formed in theouter surface 42 of the second tubular member 18. A third line ofweakness 54 is defined in this embodiment by a diametrical groove formedin the inside surface 58 of the second tubular member 18. The threelines of weakness 46, 50, and 54 each encourage local deformation of thetubular member 18 in a radial direction that tends to cause the grooveto close. It will be appreciated that in embodiments where the line ofweakness is defined by other than a groove, the radial direction ofmovement will be the same but since there is no groove, there is no“close of the groove.” Rather, in such an embodiment, the material thatdefines a line of weakness will flow or otherwise allow radial movementin the direction indicated. The three lines of weakness togetherencourage deformation of the tubular member 18 in a manner that createsa feature such as the sealable member 22 in the actuated position 30.The feature is created, then, upon the application of an axiallydirected mechanical compression of the tubular member 18 such that theactuated position 30 of the sealable member 22 is formed as the tubularmember 18 is compressed to a shorter overall length. Other mechanismscan alternatively be employed to actuate the tubular member 18 betweenthe unactuated 26 and the actuated 30 positions of the sealable member22. For example, the sealable member 22 may be repositioned to theactuated position 30 by pressurizing the inner surface 38, for example.

The tubular valve 10 has the further capability however of allowing thesealable member 22 to be repeatedly repositioned. More specifically thesealable member 22 may be repeatedly repositioned to the unactuatedposition 26 (FIG. 1), or any position between the fully unactuatedposition 26 and the fully actuated position 30 (FIG. 2). Thisvariability of extension of the sealable member 22 allows the fluidflowing through the annular space 34 to be choked to any desirablelevel. Such repositioning is effected, in one embodiment, by theapplication of an axially tensive load on the second tubular member 18,thereby elongating the second tubular member 18 in the process. Control,therefore, of the amount of extension of the sealable member 22 into theannular space 34, in this embodiment, is determined by the amount ofaxial compression or elongation of the second tubular member 18 aboutthe sealable member 22.

Compression and elongation of the second tubular member 18 can becontrolled by relative movement of a first portion 62, of the secondtubular member 18, with respect to a second portion 66, of the secondtubular member 18. Similarly, movement of the first tubular member 14relative to the second portion 66 can control the same compression andelongation, since the first portion 62 is attached to the first tubularmember 14 by, for example, threads 70. As such, since there is norelative motion between the first portion 62 and the first tubularmember 14, motion of the second portion 66 can be made relative toeither the first portion 62 or the first tubular member 14 therebycontrolling the actuation of the tubular valve 10.

The annular space 34, through which the sealable member 22 extends,defines a fluidic flow path that is to be throttled or choked by anamount of actuation of the sealable member 22. Thus, choke control of adesired flow path can be achieved by fluidically connecting the desiredflow path to the annular space 34. For example, a port 76 that extendsradially through the first tubular member 14 positioned downhole of thesealable member 22 provides flow from radially outside the first tubularmember 14 into the annular space 34. In such an embodiment the flow fromoutside the first tubular member 14 to an uphole directed annulus 80 iscontrollable via the sealable member 22. In an alternate embodiment,such as one where the uphole directed annulus 80 is dead headed, forexample, a port 84 through the second portion 66 of the second tubularmember 18 can fluidically connect the annular space 34, uphole of thesealable member 22 to an inside of the second tubular member 18. In sodoing the tubular valve 10 can control flow in either direction betweenthe outside of the first tubular member 14 to the inside of the secondtubular member 18.

In one embodiment disclosed in FIGS. 1 and 2 the sealable member 22 isan integral part of one of the two tubular members 14, 18 and thetubular members 14, 18 may both be made of metal. In such an embodimentthe seal created between the sealable member 22 and the first tubularmember 14 is a metal-to-metal seal. Such a metal-to-metal seal can haveexcellent durability in a high pressure, high temperature and causticenvironment commonly experienced in wellbores.

Referring to FIGS. 3 and 4 an alternate embodiment of the tubular valve110 with an elastomeric seal is illustrated. The tubular valve 110includes a first tubular member 114, a second tubular member 118 and asealable member 122. The sealable member 122 is supported by the secondtubular member 118 and is sealably engagable with the first tubularmember 114 in response to a selectable repositioning of the sealablemember 122. Referring specifically to FIG. 3, the sealable member 122 isnot sealably engaged with the first tubular member 114 when the sealablemember 122 is in an unactuated position 126 as shown. Referringspecifically to FIG. 4, the sealable member 122 is sealably engaged withthe first tubular member 114 when the sealable member 122 is in anactuated position 130 as shown. An annular space 134 exists between aninner surface 138, of the first tubular member 114, and an outer surface142, of the second tubular member 118, and provides a fluid flow paththerethrough. In the actuated position 130 the sealable member 122sealably engages the surface 138 thereby fully occluding the annularspace 134 and closing the tubular valve 110 to fluidic flowtherethrough. By contrast, in the unactuated position 126 the sealablemember 122 does not occlude the annular space 134 at all and therebydefines a fully open condition of the tubular valve 110. The sealablemember 122 can also occlude a fractional portion of the annular space134 between fully closed and fully open. When doing so the amount ofocclusion varies in proportion to the amount of extension of thesealable member 122 between the unactuated 126 and the actuated 130positions. It should be noted that while the foregoing embodiment hasthe sealable member 122 supported by the second tubular member 118,alternate embodiments could have a sealable member supported by, orintegrated into, the first tubular member 114. Such an alternateembodiment could have a sealable member extend radially inwardly tosealably engage with the outer radial surface 142 of the second tubularmember 118, for example. Multiple sealable members could also beincorporated into embodiments as will be discussed in detail below.

Repositioning of the sealable member 122, supported by the secondtubular member 118, is due to construction thereof. The sealable member122 is formed from an elastomeric band 146 that circumferentiallysurrounds a reduced dimension portion 150 of an uphole portion 154 ofthe second tubular member 118. The elastomeric band 146 is positionedaxially between the uphole portion 154 and a downhole portion 158 of thesecond tubular member 118. Movement of the uphole portion 154 towardsthe downhole portion 158 compresses the elastomeric band 146 axiallywhich results in the elastomeric band 146 increasing in sizediametrically until the band 146 males contact with the inner surface138. The actuated position 130 is created, then, upon the application ofan axially directed mechanical compression of the tubular member 118such that the actuated position 130 of the sealable member 122 is formedas the tubular member 118 is compressed to a shorter overall length.

The tubular valve 110 has the further capability however of allowing thesealable member 122 to be repeatedly repositioned. More specifically thesealable member 122 may be repeatedly repositioned to the unactuatedposition 126 (FIG. 1), or any position between the fully unactuatedposition 126 and the fully actuated position 130 (FIG. 2). Thisvariability of extension of the sealable member 122 allows the fluidflowing through the annular space 134 to be choked to any desirablelevel. Such repositioning is effected, in one embodiment, by theapplication of an axially tensive load on the second tubular member 118,thereby elongating the second tubular member 118 in the process.Control, therefore, of the amount of extension of the sealable member122 into the annular space 134, in this embodiment, is determined by theamount of axial compression or elongation of the second tubular member118 about the sealable member 122.

Compression and elongation of the second tubular member 118 can becontrolled by relative movement of the uphole portion 154 with respectto the downhole portion 158 of the second tubular member 118. Similarly,relative movement of the uphole portion 154 relative to the firsttubular member 114 can control this compression and elongation, sincethe downhole portion 158 is attached to the first tubular member 114 bythreads 162. As such, since there is no relative motion between thedownhole portion 158 and the first tubular member 114, motion of theuphole portion 154 can be made relative to either the downhole portion158 or the first tubular member 114. Thus controlling these relativemotions can control the actuation of the tubular valve 110.

The annular space 134, through which the sealable member 122 extends,defines a fluidic flow path that is to be throttled or choked by anamount of actuation of the sealable member 122. Thus, choke control of adesired flow path can be achieved by fluidically connecting the desiredflow path to the annular space 134. For example, a port 176 that extendsradially through the first tubular member 114 positioned downhole of thesealable member 122 provides flow from radially outside the firsttubular member 114 into the annular space 134. In such an embodiment theflow from outside the first tubular member 114 to an uphole directedannulus 180 is controllable via the sealable member 122. In an alternateembodiment, such as one where the uphole directed annulus 180 is deadheaded, for example, a port 184 through the uphole portion 154 of thesecond tubular member 118 can fluidically connect the annular space 134,uphole of the sealable member 122 to an inside of the second tubularmember 118. In so doing the tubular valve 110 can control flow in eitherdirection between the outside of the first tubular member 114 to theinside of the second tubular member 118. It should be noted thatalthough components are labeled herein with terms such as uphole (i.e.uphole portion) and downhole (i.e. downhole portion), these terms areonly used to define relative positioning of the components and as suchcould have these terms reversed or replaced with other terms to definerelative positioning of the components.

Referring to FIG. 5 an alternative embodiment of the tubular valve 210is illustrated. The tubular valve 210 includes a first tubular member214, a second tubular member 218, a first sealable member 220, and asecond sealable member 222. In this embodiment the sealable members 220and 222 are supported by the second tubular member 218 and are sealablyengagable with the first tubular member 214 in response to a selectableposition of the sealable members 220, 222. The sealable member 220 isnot sealably engaged with the first tubular member 214 as the sealablemember 220 is in an unactuated position 226 as shown. The sealablemember 222 is sealably engaged with the first tubular member 214 as thesealable member 222 is in an actuated position 230 as shown. An annularspace 234 exists between an inner surface 238, of the first tubularmember 214, and an outer surface 242, of the second tubular member 218,and provides a fluid flow path therethrough. In the actuated position230 the sealable member 222 sealably engages the surface 238 therebyfully occluding the annular space 234. By contrast, in the unactuatedposition 226 the sealable member 220 does not occlude the annular space234 at all. The sealable members 220, 222 can also occlude a fractionalportion of the annular space 234 between fully closed and fully open.When doing so the amount of occlusion varies in proportion to the amountof extension of the sealable members 220, 222 between the unactuated 226and the actuated 230 positions. It should be noted that while theforegoing embodiment has the sealable members 220, 222 supported by thesecond tubular member 218, alternate embodiments could have sealablemembers supported by, or integrated into, the first tubular member 214.Such an alternate embodiment could have sealable members extend radiallyinwardly to sealably engage with the outer radial surface 242 of thesecond tubular member 218, for example. Alternatively, embodiments couldalso have one or more sealable members supported by or integrated intothe second tubular member 218 and simultaneously have one or moresealable members supported by or integrated into the first tubularmembers 214.

Repositioning of the sealable members 220, 222, in the second tubularmember 218, is due to construction thereof. The sealable members 220,222 are formed from sections of the second tubular member 218 in thesame way that the sealable member 22 of FIGS. 1 and 2 is formed of asection of the second tubular member 18 and therefore will not bedescribed in detail again here. One difference, however, in thisembodiment is that tubular valve 210 has two sealable members 220 and222, and thus a third portion 260 of the second tubular member 218 ismovable relative to a first portion 262 and a second portion 266 of thetubular member 218. In fact, by having each portion 260, 262, 266 bemovable independently relative to each of the other portions 260, 262,266, the two sealable members 220 and 222 are independently extendableto any desired amount of extension. It should be noted that alternateembodiments could have more than two sealable members 220, 222. And,regardless of how many sealable members 220, 222 are used, each could beindependently repositionable.

In the embodiment of the tubular valve 210, for example, the first twosealable members 220, 222 could be repositioned independently of oneanother. To do so simply requires independent control over the movementof the three portions 260, 262 and 266 relative to one another. Movingthe third portion 266 relative to the portions 262, 260, heldstationary, for example, will allow repositioning of the second sealablemember 222 without repositioning the first sealable member 220.Similarly, by moving the third portion 266 and the second portion 262 inunison relative to the first portion 260, held stationary, allows forrepositioning of the first sealable member 220 without repositioning ofthe second sealable member 222. Thus, a series of valves can beindependently controllable to choke fluid flow therethrough.Additionally, the valves can be set to control fluid flow in variousways depending upon how the annular space 234 about the sealable members220, 222 is ported. The embodiment of the tubular valve 210, describedbelow, is one example of how improved resolution of choke control can beattained through porting.

In an embodiment of the tubular valve 210 a first ports 276 in the firsttubular member 214 includes multiple ports 276 a, 276 b, 276 c and soforth. Having a plurality of ports 276 allows for an additional level offlow control between the ports 276 and a second port 280, for example,located in the second tubular member 218. This additional level of flowcontrol results from the axial movement of the second sealable member222, relative to the ports 276, provided by repositioning of the firstsealable member 220. For example, the ports 276 c and 276 d could belocated downhole of the sealable member 222 while the ports 276 a and276 b could be located uphole of the sealable member 222, as shown.Then, in response to repositioning of the first sealable member 220, thesecond sealable member 222 can move in a downhole direction relative tothe ports 276. Such movement could be settable, based upon the geometryof the first sealable member 220 and the spacing of the ports 276, suchthat all of the ports 276 are located uphole of the second sealablemember 222, for example. Resolution could be increased further still byselective distribution of the ports 276 about the first tubular member214. For example, the ports 276 can be distributed axially,perimetrically or a combination of both axially and perimetricallyrelative to the tubular member 214. It should be noted that whilerepositioning of the first sealable member 220 causes axial movement ofthe second sealable member 222 it also results in a change in theextension of the first sealable member 220 into the annular space 234,which in itself will effect the choking level of the fluid therethrough.An alternate embodiment that provides for axial movement of a sealablemember relative to ports without choking in an alternate location willbe reviewed below.

Referring to FIG. 6 a partial cross sectional view of an alternateembodiment of the tubular valve 310 that incorporates a plurality ofmetal sealable members is illustrated. A first tubular member 314 has aport 318 extending through a wall 322 thereof. The port 318 permitsfluid communication between an outside of the first tubular member 314and annular flow channels to be described in more detail below. A secondtubular member 324 is coaxially located radially inwardly of the firsttubular member 314 and is axially slidably engaged with the firsttubular member 314. The tubular members 314, 324 are made of a rigidmaterial such as metal, for example. The second tubular member 324supports a first sealable member 332 and a second sealable member 334.Both sealable members 332, 334 fully occlude an annular space 336 thatexists between an outer surface 340, of the second tubular member 324,and an inner surface 344, of the first tubular member 314. The sealablemembers 332, 334 are made of metal and are elastically deformable and assuch are deformed radially by the compression between the surfaces 340and 344. The elastic deformation of the sealable members 332, 334maintains a sealing force between outward extensions 348, of sealablemembers 332, 334, and the surface 344 and inward extensions 352, ofsealable members 332, 334 and the surface 340.

The forgoing structure allows the tubular valve 310 to selectively portthe outside of the first tubular member 314 with either a first annularflow channel 356 or a second annular flow channel 360 that existsbetween the first tubular member 314 and the second tubular member 324.The first annular flow channel 356 is positioned between the sealablemembers 332, 334 while the second annular flow channel 360 is positionedon an uphole side (shown in FIG. 6) or a downhole side of the sealablemembers 332, 334. By selective axially movement of the second tubularmember 324 relative to the first tubular member 314 the port 318 can befluidically coupled to only the first annular flow channel 356, only thesecond annular flow channel 360 or a portion of both annular flowchannel 356, 360. As such, the tubular valve 310 can be used to chokethe flow between either channel 356, 360 and the exterior of the firsttubular member 314. It should be noted, however, that by positioning theport 318 in the second tubular member 324 the flow control can bebetween the either channel 356, 360 and the interior of the secondtubular member 324. Additionally, by placing ports in both tubularmembers 314, 324 flow control can be established between the outside ofthe first tubular member 314 and the inside of the second tubular member324. The port 318, in alternate embodiments, may include a plurality ofports arranged axially only, perimetrically only, or both axially andperimetrically about a circumference of the tubular member 314 tothereby increase resolution of the flow control provided per unit ofmovement of the tubular members 314, 324 relative to one another.

While the invention has been described with reference to an exemplaryembodiment or embodiments, it will be understood by those skilled in theart that various changes may be made and equivalents may be substitutedfor elements thereof without departing from the scope of the invention.In addition, many modifications may be made to adapt a particularsituation or material to the teachings of the invention withoutdeparting from the essential scope thereof. Therefore, it is intendedthat the invention not be limited to the particular embodiment disclosedas the best mode contemplated for carrying out this invention, but thatthe invention will include all embodiments falling within the scope ofthe claims.

1. A valve comprising: a first tubular member having at least one portextending through a wall thereof; and a second tubular member at leastpartially radially aligned with the first tubular member, the firsttubular member and the second tubular member being sealably connected atan interface therebetween, one of the first tubular member and thesecond tubular member supporting at least one sealable member capable ofsealingly engaging the other of the first tubular member and the secondtubular member, and having a portion movable relative to the interface,the movable portion being located on a first side of the at least onesealable member that is opposite a second side of the at least onesealable member on which the interface is located.
 2. The valve asclaimed in claim 1 wherein the at least one sealable member is a metalseal.
 3. The valve as claimed in claim 2 wherein the at least one metalseal is two metal seals disposed such that the at least one port isdisposed between the two seals.
 4. The valve as claimed in claim 3wherein the seals are displaceable sufficiently in at least onedirection pursuant to relative movement between the first tubular memberand the second tubular member to position at least a portion of the atleast one port such that both of the two seals are on one side of the atleast a portion of the at least one port.
 5. The valve as claimed inclaim 1 wherein the at least one port is a plurality of ports arrangedperimetrically about the first tubular member.
 6. The valve as claimedin claim 1 wherein the at least one port is a plurality of portsarranged axially along the first tubular member.
 7. The valve as claimedin claim 1 wherein the second tubular member includes at least one portthrough a wall thereof, axially displaced from the at least one port inthe first tubular member.
 8. The valve as claimed in claim 7 wherein theat least one sealable member includes at least one selectivelydeformable member, the at least one sealable member being variablyrepositionable via deformation between fully occluding an annular spacebetween the first tubular member and the second tubular member and fullyretracted from the annular space.
 9. The valve as claimed in claim 8wherein the at least one selectively deformable member is metal.
 10. Thevalve as claimed in claim 9 wherein the at least one selectivelydeformable member has a tubular shape defining a wall, the wall havingat least three circumferential lines of weakness, the first and thesecond of the lines of weakness being on one of an inner and an outersurface of the wall and the third line of weakness being on the oppositeof the inner and the outer surface of the wall from that on which thefirst and the second lines of weakness are located, the three lines ofweakness being separated from each other along an axial direction of theat least one deformable member, the third line of weakness beingpositioned axially between the first and the second lines of weaknessdefining a direction of deformation responsive to an axially compressiveforce on the at least one deformable member.
 11. The valve as claimed inclaim 10 wherein the first and the second lines of weakness are in theouter surface of the wall and the third line of weakness is on an innersurface of the wall such that the deformable member deforms in adirection substantially radially outwardly in response to application ofan axially compressive force.
 12. The valve as claimed in claim 10wherein the at least one deformable member is integrally formed in thefirst tubular member or the second tubular member.
 13. The valve asclaimed in claim 10 wherein the lines of weakness comprise open grooves.14. The valve as claimed in claim 8 wherein the deformable member ispositioned axially between the at least one port of the first tubularmember and the at least one port of the second tubular member.
 15. Thevalve as claimed in claim 7 wherein the at least one port in the firsttubular member is a number of axially spaced ports, and the at least onesealable member is a first selectively deformable member, the valvefurther comprising a second selectively deformable member, the firstselectively deformable member being variably repositionable viadeformation between fully occluding an annular space between the firsttubular member and the second tubular member and fully retracted fromthe annular space, the second selectively deformable member beingpositionable to selectively allow, choke or prevent flow between fewerthan all of the number of axially spaced ports and the at least one portof the second tubular member.
 16. The valve as claimed in claim 15wherein the first and second deformable members deform sequentially. 17.The valve as claimed in claim 15 wherein the first and second deformablemembers deform independently.
 18. The valve as claimed in claim 1wherein the at least one sealable member is an elastomeric seal.
 19. Avalve comprising: a first tubular member having at least one portextending through a wall thereof; a second tubular member radiallyaligned with and moveable relative to the first tubular member; one ofthe first tubular member and the second tubular member supporting atleast two metal members capable of sealingly engaging the other of thefirst tubular member and the second tubular member.
 20. The valve asclaimed in claim 19 wherein the two metal members are radiallycompressed between the first tubular member and the second tubularmember.
 21. A method for controlling fluid flow comprising: selectivelydeforming at least one selectively deformable member disposed betweentwo tubular members that are radially aligned with one another, at leastone of the at least one deformable member being positioned between afluid inlet and a fluid outlet; and regulating flow of fluid bydeforming the at least one deformable member positioned between thefluid inlet and the fluid outlet sufficiently to achieve a desired flowrate.
 22. The method as claimed in claim 21 wherein the deforming is byapplication of axial load on at least one of the tubular members. 23.The method as claimed in claim 22 wherein the load is compressive.